Wireless communication module

ABSTRACT

A ground layer is disposed within a dielectric substrate. An antenna pattern that operates as an antenna is disposed so as to be closer to a first surface of the dielectric substrate than the ground layer is. A high-frequency device that supplies a high-frequency signal to the antenna pattern is mounted in or on a second surface of the dielectric substrate, which is opposite to the first surface. A plurality of signal conductor columns and a plurality of ground conductor columns that are made of a conductive material project from the second surface. Each of the signal conductor columns is connected to the high-frequency device by a wiring pattern, which is provided in or on the dielectric substrate, and the ground conductor columns are connected to the ground layer.

This is a continuation of U.S. patent application Ser. No. 15/491,263filed Apr. 19, 2017, which is a continuation of InternationalApplication No. PCT/JP2015/078920 filed on Oct. 13, 2015 which claimspriority from Japanese Patent Application No. 2014-213292 filed on Oct.20, 2014. The contents of these applications are incorporated herein byreference in their entireties.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

The present disclosure relates to a wireless communication module thatincludes a high-frequency device and an antenna.

Description of the Related Art

Patent Document 1 and Patent Document 2 each disclose anantenna-integrated module that includes an antenna and a high-frequencysemiconductor device integrated with each other.

The antenna-integrated module disclosed in Patent Document 1 has amultilayer structure in which a first semiconductor layer, a firstdielectric substrate, a second semiconductor layer, a second dielectricsubstrate, and a third semiconductor layer are stacked on top of oneanother in this order. The first semiconductor layer includes a firstground conductor and a microstrip antenna. The second semiconductorlayer includes a second ground conductor. The third semiconductor layerincludes a third ground conductor and a power supply circuit.

A high-frequency device is mounted in or on a surface of the seconddielectric substrate, in or on which a power supply circuit is formed. Acoupling hole is formed in the second ground conductor. The power supplycircuit and the microstrip antenna are coupled to each other via thecoupling hole. The first ground conductor, the second ground conductor,and the third ground conductor are connected to one another via throughholes. With this configuration, the ground of a high-frequency circuitcan be stabilized.

In the antenna-integrated module disclosed in Patent Document 2, awireless region and an antenna region are defined in or on one surfaceof a dielectric substrate. A high-frequency device is mounted in thewireless region. The wireless region and the antenna region are coatedwith a sealing-resin layer. The high-frequency device in the wirelessregion is also coated with the sealing-resin layer. A radiating elementof an antenna and a shield layer shielding the high-frequency device aresimultaneously formed on the sealing-resin layer.

Patent Document 1: Japanese Patent No. 3472430

Patent Document 2: Japanese Unexamined Patent Application PublicationNo. 2014-179821

BRIEF SUMMARY OF THE DISCLOSURE

In the antenna-integrated module disclosed in Patent Document 1, thehigh-frequency device is not shielded. In the antenna-integrated moduledisclosed in Patent Document 2, it is difficult to arrange the radiatingelement and a ground conductor in a multilayer manner. In order to causea millimeter-wave antenna to favorably operate, it is desirable that theradiating element and the ground conductor be arranged in a multilayermanner.

It is an object of the present disclosure to provide a wirelesscommunication module capable of effectively shielding a high-frequencydevice and arranging an antenna pattern, which operates as an antenna,and a ground conductor in a multilayer manner.

A wireless communication module according to a first aspect of thepresent disclosure includes a dielectric substrate, a ground layer thatis disposed within the dielectric substrate, an antenna pattern that isdisposed so as to be closer to a first surface of the dielectricsubstrate than the ground layer is and that operates as an antenna, ahigh-frequency device that is mounted in or on a second surface of thedielectric substrate, which is opposite to the first surface, and thatsupplies a high-frequency signal to the antenna pattern, and a pluralityof signal conductor columns and a plurality of ground conductor columnsthat project from the second surface and that are made of a conductivematerial. Each of the signal conductor columns is connected to thehigh-frequency device by a wiring pattern, which is provided in or onthe dielectric substrate. The ground conductor columns are connected tothe ground layer. An end of each of the plurality of signal conductorcolumns and an end of each of the plurality of ground conductor columnsare electrically connected to terminals of a mounting substrate.

Unnecessary radiation from the high-frequency device can be blocked bythe ground layer in the dielectric substrate and the ground conductorcolumns. In addition, unnecessary radiation from the high-frequencydevice can be blocked by a ground layer in the mounting substrate.

In addition to the configuration of the wireless communication moduleaccording to the first aspect of the present disclosure, in the wirelesscommunication module according to a second aspect of the presentdisclosure, the antenna pattern includes a plurality of dipole antennasthat are arranged along at least a portion of an outer periphery of thedielectric substrate. The wireless communication module further includesa reflector pattern that is positioned further inside than the dipoleantennas when viewed in plan view and that serves as a reflector of thedipole antennas and an interlayer connection conductor that connects thereflector pattern to the plurality of ground conductor columns. Theground conductor columns serve as reflectors of the dipole antennastogether with the reflector pattern.

Since the reflector pattern and the ground conductor columns serve asreflectors, radiation efficiency (antenna gain) of the dipole antennascan be improved.

In addition to the configuration of the wireless communication moduleaccording to the second aspect of the present disclosure, in thewireless communication module according to a third aspect of the presentdisclosure, the antenna pattern further includes a plurality of patchantennas that are positioned further inside than the dipole antennas.

Each of the dipole antennas has directivity in the lateral direction ofthe wireless communication module, and each of the patch antennas hasdirectivity in a direction normal to the wireless communication module(boresight direction).

In addition to the configurations of the wireless communication modulesaccording to the first to third aspects of the present disclosure, inthe wireless communication module according to a fourth aspect of thepresent disclosure, the antenna pattern is configured to operate in abandwidth of 60 GHz. The plurality of ground conductor columns arearranged so as to surround the high-frequency device when viewed in planview. A center-to-center distance between the adjacent ground conductorcolumns is not more than one-quarter an effective wavelength of radiowaves at a frequency of 30 GHz.

Unnecessary radiation at a frequency of 30 GHz or lower can beeffectively blocked.

In addition to the configuration of the wireless communication moduleaccording to the third aspect of the present disclosure, in the wirelesscommunication module according to the fourth aspect of the presentdisclosure, the center-to-center distance between the adjacent groundconductor columns is not more than one-twelfth the effective wavelengthof radio waves at a frequency of 30 GHz.

The second harmonic wave and the third harmonic wave of unnecessaryradiation at a frequency of 30 GHz or lower can be effectively blocked.

In addition to the configurations of the wireless communication modulesaccording to the first to fifth aspects of the present disclosure, thewireless communication module according to the fifth aspect of thepresent disclosure further includes a sealing-resin layer that isdisposed on the second surface of the dielectric substrate and in whichthe high-frequency device, the signal conductor columns, and the groundconductor columns are to be embedded.

Since the signal conductor columns and the ground conductor columns areembedded in the sealing-resin layer, the signal conductor columns andthe ground conductor columns are further reliably and mechanicallysupported. The high-frequency device is protected by the sealing-resinlayer. By thermally coupling the sealing-resin layer to the mountingsubstrate, the heat-dissipation characteristic of the high-frequencydevice can be improved.

In addition to the configurations of the wireless communication modulesaccording to the first to sixth aspects of the present disclosure, thewireless communication module according to the sixth aspect of thepresent disclosure further includes a frame-shaped substrate that isjoined to the second surface of the dielectric substrate and thatsurrounds the high-frequency device when viewed in plan view. The signalconductor columns and the ground conductor columns are accommodated inthrough holes, which are formed in the frame-shaped substrate.

The signal conductor columns and the ground conductor columns arereliably and mechanically supported by the frame-shaped substrate.

Unnecessary radiation from a high-frequency device can be blocked by aground layer within a dielectric substrate and ground conductor columns.In addition, unnecessary radiation from a high-frequency device can beblocked by a ground layer within a mounting substrate.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1A is a cross-sectional view of a wireless communication moduleaccording to a first embodiment of the present disclosure. FIG. 1B is across-sectional view of a wireless communication module according to afirst modification of the first embodiment. FIG. 1C is a cross-sectionalview of a wireless communication module according to a secondmodification of the first embodiment.

FIG. 2A is a plan sectional view of the uppermost semiconductor layer ofa dielectric substrate, and FIG. 2B is a plan sectional view of thesecond semiconductor layer.

FIG. 3A is a plan sectional view of the third semiconductor layer of thedielectric substrate, and FIG. 3B is a bottom view of the wirelesscommunication module.

FIG. 4A is a side view of the wireless communication module according tothe first embodiment, and FIG. 4B is a cross-sectional view taken alongone-dot chain line 4B-4B of FIG. 2A.

FIG. 5A is a cross-sectional view taken along one-dot chain line 5A-5Aof FIG. 2A, and FIG. 5B is a cross-sectional view taken along one-dotchain line 5B-5B of FIG. 2A.

FIG. 6 is a cross-sectional view illustrating a state where a wirelesscommunication module according to a second embodiment is mounted in oron a mounting substrate.

FIG. 7A and FIG. 7B are respectively a bottom view and a cross-sectionalview of a wireless communication module according to a third embodiment.

DETAILED DESCRIPTION OF THE DISCLOSURE First Embodiment

FIG. 1A is a cross-sectional view illustrating a wireless communicationmodule 10 according to a first embodiment of the present disclosure anda mounting substrate 20 in or on which the wireless communication module10 is mounted. A ground layer 11 is disposed within a dielectricsubstrate 19. An antenna pattern 12 is disposed so as to be closer to afirst surface 19A of the dielectric substrate 19 than the ground layer11 is. The antenna pattern 12 operates as a radiating element thatradiates radio waves. Note that the antenna pattern 12 may be disposedon the first surface 19A. The antenna pattern 12 includes, for example,patch antennas, printed dipole antennas, and the like.

A high-frequency device (high-frequency semiconductor integrated circuitelement) 13 is mounted in or on a second surface 19B of the dielectricsubstrate 19 that is opposite to the first surface 19A. A terminal ofthe high-frequency device 13 and the antenna pattern 12 is connected toeach other by one of feeders 14. The high-frequency device 13 supplies ahigh-frequency signal to the antenna pattern 12 via the feeder 14. Ahigh-frequency signal received by the antenna pattern 12 is input to thehigh-frequency device 13 via the feeder 14.

A plurality of signal conductor columns 15 and a plurality of groundconductor columns 16 project from the second surface 19B of thedielectric substrate 19. The signal conductor columns 15 are connectedto the high-frequency device 13 by wiring patterns 17, which areprovided in or on the dielectric substrate 19. The ground conductorcolumns 16 are connected to the ground layer 11.

In the wireless communication module 10, an end of each of the pluralityof signal conductor columns 15 and an end of each of the plurality ofground conductor columns 16 are electrically connected to terminals 21of the mounting substrate 20. The mounting substrate 20 is, for example,a motherboard in or on which a central processing unit (CPU), a basebandintegrated circuit element, and the like are mounted. A ground layer 22is disposed within the mounting substrate 20. The ground layer 22 isconnected to the ground layer 11 of the wireless communication module 10by the ground conductor columns 16.

In the first embodiment, not only the ground layer 11 of the wirelesscommunication module 10 but also the ground layer 22 of the mountingsubstrate 20 operate as ground planes that are paired with the antennapattern 12. Thus, a ground plane larger than the plane dimension of thewireless communication module 10 can be ensured. As a result of theground plane becoming large, the operations of the antennas arestabilized.

The high-frequency device 13 is shielded by the ground layer 11, whichis disposed above the high-frequency device 13, and the ground layer 22,which is disposed below the high-frequency device 13. Thus, unnecessaryradiation from the high-frequency device 13 in upward and downwarddirections can be effectively blocked. In addition, by setting thecenter-to-center distance between the plurality of ground conductorcolumns 16 to be one-quarter or less of the effective wavelength ofspurious radiation from the high-frequency device 13, spurious radiationfrom the high-frequency device 13 in the lateral direction can beeffectively suppressed. By setting the center-to-center distance betweenthe ground conductor columns 16 to be one-twelfth or less of theeffective wavelength of the spurious radiation, radiation of the secondharmonic wave and the third harmonic wave of the spurious radiation canalso be effectively suppressed. Here, the term “effective wavelength”refers to the actual wavelength considering the dielectric constant in aregion that is focused on.

FIG. 1B illustrates a cross-sectional view of the wireless communicationmodule 10 according to a first modification of the first embodiment. Thedifference between the first modification and the first embodiment,which is illustrated in FIG. 1A, will be described below, and thedescription of the configuration common to the first modification andthe first embodiment will be omitted. In the first modification of thefirst embodiment, the second surface 19B of the dielectric substrate 19,the high-frequency device 13, the signal conductor columns 15, and theground conductor columns 16 are embedded in a sealing-resin layer 25.The sealing-resin layer 25 is formed by injecting a resin after thesignal conductor columns 15 and the ground conductor columns 16 havebeen joined to the second surface 19B of the dielectric substrate 19. Anend of each of the signal conductor columns 15 and an end of each of theground conductor columns 16 are exposed at the sealing-resin layer 25.

In the first modification of the first embodiment, the sealing-resinlayer 25 faces the mounting substrate 20, and thus, the coplanaritybetween the wireless communication module 10 and the mounting substrate20 can be easily ensured. For example, the high-frequency device 13 andthe like, which are components mounted in or on the second surface 19Bof the dielectric substrate 19, are protected by the sealing-resin layer25, and thus, a high reliability can be ensured. In addition, bythermally coupling the sealing-resin layer 25 and the mounting substrate20 to each other, heat generated by the high-frequency device 13 can beeffectively transferred to the mounting substrate 20. As a result, theheat-dissipation characteristic of the high-frequency device 13 can beimproved.

FIG. 1C illustrates a cross-sectional view of the wireless communicationmodule 10 according to a second modification of the first embodiment.The difference between the second modification and the first embodiment,which is illustrated in FIG. 1A, will be described below, and thedescription of the configuration common to the second modification andthe first embodiment will be omitted. In the second modification of thefirst embodiment, a frame-shaped substrate 26 is joined to the secondsurface 19B of the dielectric substrate 19. The frame-shaped substrate26 surrounds the high-frequency device 13 when viewed in plan view. Thesignal conductor columns 15 and the ground conductor columns 16 areaccommodated in through holes formed in the frame-shaped substrate 26.After filling the through holes with the signal conductor columns 15 andthe ground conductor columns 16, the frame-shaped substrate 26 is joinedto the dielectric substrate 19.

In the second modification of the first embodiment, the frame-shapedsubstrate 26 faces the mounting substrate 20, and thus, the coplanaritybetween the wireless communication module 10 and the mounting substrate20 can be easily ensured. In addition, since the signal conductorcolumns 15 and the ground conductor columns 16 are accommodated in thethrough holes of the frame-shaped substrate 26, the mechanical strengthof each of the signal conductor columns 15 and the mechanical strengthof each of the ground conductor columns 16 can be enhanced.

Second Embodiment

The wireless communication module 10 according to the second embodimentwill now be described with reference to FIG. 2A to FIG. 5B. The wirelesscommunication module 10 according to the second embodiment includes thedielectric substrate 19 that includes a plurality of semiconductorlayers.

FIG. 2A illustrates a plan sectional view of the uppermost semiconductorlayer of the dielectric substrate 19. The dielectric substrate 19 has arectangular or square planar shape. The uppermost semiconductor layerincludes a plurality of printed dipole antennas 30, a plurality offeeders 31, a plurality of baluns (balanced-to-unbalanced transformers)32, and conductor patterns 38 of a plurality of patch antennas. Thedielectric substrate 19 is made of, for example, an epoxy resin or thelike. The dipole antennas 30, the feeders 31, the baluns 32, and theconductor patterns 38 of the plurality of patch antennas are made of,for example, a conductive material such as copper. Similarly, the otherlower semiconductor layers are also made of a conductive material suchas copper.

The plurality of dipole antennas 30 are arranged along the outerperipheral line of the dielectric substrate 19 so as to be positionedslightly further inside than the outer peripheral line. Each of thedipole antennas 30 is disposed so as to be parallel to the outerperipheral line of the dielectric substrate 19. As an example, three ofthe dipole antennas 30 are arranged so as to correspond to one of thesides of the dielectric substrate 19.

Each of the balanced feeders 31 extends from a corresponding one of thedipole antennas 30 toward the inside of the dielectric substrate 19. Thebaluns (balanced-to-unbalanced transformers) 32 are disposed at innerend portions of the corresponding feeders 31. Each of the baluns 32causes the phase of one of the corresponding balanced feeders 31 and thephase of the other of the corresponding balanced feeders 31 to bedifferent from each other by 180 degrees. The baluns 32 are connectedto, at connection points 36, transmission lines of one of the innerlayers of the dielectric substrate 19.

A reflector pattern 33 is disposed so as to be positioned slightlyfurther inside than the dipole antennas 30 and positioned slightlyfurther outside than the baluns 32. The reflector pattern 33 is formedof a linear conductor pattern that is disposed along the outerperipheral line of a rectangular shape slightly smaller than thedielectric substrate 19. The reflector pattern 33 is cut at positionsthat cross the feeders 31 so as to be insulated from the feeders 31. Thegap between each of the dipole antennas 30 and the reflector pattern 33is equal to one fourth of the effective wavelength of radio waves at theoperating frequency of each of the dipole antennas 30. The reflectorpattern 33 is connected to, at a plurality of connection points 34arranged along the reflector pattern 33, the ground layer included inone of the inner layers.

The conductor patterns 38 of the plurality of patch antennas arearranged in a matrix so as to be positioned further inside than thedipole antennas 30. In the example illustrated in FIG. 1A, the conductorpatterns 38 are arranged in a matrix having two rows and three columns.The row direction and the column direction are parallel to the outerperipheral line of the dielectric substrate 19.

FIG. 2B illustrates a plan sectional view of the second semiconductorlayer of the dielectric substrate 19 from the top. A ground layer 40 ispositioned at the second layer. When viewed in plan view, the outerperiphery of the ground layer 40 matches the reflector pattern 33 (FIG.2A) of the uppermost layer. A plurality of openings 41 and a pluralityof openings 42 are formed in the ground layer 40.

The openings 41 are positioned so as to correspond to the conductorpatterns 38 (FIG. 2A) of the patch antennas of the uppermost layer. Eachof the openings 41 has a square planar shape larger than thecorresponding conductor pattern 38.

The openings 42 are arranged at positions corresponding to theconnection points 36 (FIG. 2A) of the baluns 32. Interlayer connectionconductors 43 are disposed in the openings 42. The interlayer connectionconductors 43 connect the baluns 32 (FIG. 2A) of the upper layer and thetransmission lines of one of the lower layers to each other.

FIG. 3A illustrates a plan sectional view of the third semiconductorlayer of the dielectric substrate 19 from the top. A ground layer 50,feed elements 51, transmission lines 52, and interlayer connectionconductors 53 are disposed in or on the third layer. The ground layer 50has a frame-like planar shape and is connected to the reflector pattern33 (FIG. 2A) of the uppermost layer and the ground layer 40 (FIG. 2B) ofthe second layer. When viewed in plan view, the outer peripheral line ofthe ground layer 50 matches the reflector pattern 33 (FIG. 2A). The feedelements 51, the transmission lines 52, and the interlayer connectionconductors 53 are arranged in a region surrounded by the frame-shapedground layer 50. The transmission lines 52 and the interlayer connectionconductors 53 are connected to the baluns 32 (FIG. 2A) of the uppermostlayer.

FIG. 3B illustrates a bottom view of the wireless communication module10. The sealing-resin layer 25 is in close contact with the bottomsurface of the dielectric substrate 19 (FIG. 2A, FIG. 2B, and FIG. 3A).A high-frequency device (high-frequency semiconductor integrated circuitelement) 13, high-frequency circuit components 18, and conductor columns29 are embedded in the sealing-resin layer 25. The high-frequencycircuit components 18 include an inductor, a capacitor, and the like.The high-frequency device 13 and the high-frequency circuit components18 are mounted in or on the rear surface of the dielectric substrate 19(FIG. 3A). The conductor columns 29 project from the rear surface of thedielectric substrate 19, and an end of each of the conductor columns 29is exposed at a surface of the sealing-resin layer 25. The conductorcolumns 29 are made of, for example, a conductive material such ascopper. The sealing-resin layer 25 is made of, for example, athermosetting resin such as an epoxy resin or a cyanate resin.

When viewed in plan view, the plurality of conductor columns 29 arearranged so as to be equally spaced along the reflector pattern 33 (FIG.2A). In other words, the conductor columns 29 are positioned furtherinside than the dipole antennas 30. The conductor columns 29 include theplurality of signal conductor columns 15 and the plurality of groundconductor columns 16. The signal conductor columns 15 are connected tothe high-frequency device 13 by wiring patterns formed in or on thedielectric substrate 19 (FIG. 2A, FIG. 2B, and FIG. 3A). The groundconductor columns 16 are connected to the ground layer 50 (FIG. 3A).

FIG. 4A illustrates a side view of the wireless communication module 10.The wireless communication module 10 includes the dielectric substrate19 and the sealing-resin layer 25. The second surface 19B that isopposite to the first surface 19A, which is the front surface of thedielectric substrate 19, is coated with the sealing-resin layer 25.

FIG. 4B is a cross-sectional view taken along one-dot chain line 4B-4Bof FIG. 2A. The dipole antennas 30 are disposed within the dielectricsubstrate 19. The dipole antennas 30 are positioned so as to be closerto the first surface 19A than the ground layer 40 (FIG. 2B), which isone of the inner layers, is.

FIG. 5A illustrates a cross-sectional view taken along one-dot chainline 5A-5A of FIG. 2A. The dipole antennas 30, the feeders 31, and thereflector pattern 33 are disposed in or on the uppermost semiconductorlayer of the dielectric substrate 19. The ground layer 40 is positionedat the second layer, and the ground layer 50 is positioned at the thirdlayer. The reflector pattern 33 and the ground layer 40, which ispositioned below the reflector pattern 33, are connected to each otherby interlayer connection conductors 35. The ground layer 40 and theground layer 50, which is positioned below the ground layer 40, areconnected to each other by interlayer connection conductors 45.

The plurality of signal conductor columns 15 and the plurality of groundconductor columns 16 are embedded in the sealing-resin layer 25. An endsurface of each of the signal conductor columns 15 and an end surface ofeach of the ground conductor columns 16 are exposed at the sealing-resinlayer 25. The ground conductor columns 16 are connected to the groundlayer 50 by interlayer connection conductors 55 in the dielectricsubstrate 19. The signal conductor columns 15 are connected to thehigh-frequency device 13 (FIG. 3B) by the wiring patterns 17 formed inor on the dielectric substrate 19. When viewed in plan view, the signalconductor columns 15 and the ground conductor columns 16 are positionedfurther inside than the dipole antennas 30.

FIG. 5B illustrates a cross-sectional view taken along one-dot chainline 5B-5B of FIG. 2A. The conductor patterns 38 of patch antennas 39are disposed in or on the uppermost semiconductor layer of thedielectric substrate 19. The ground layer 40 is positioned at the secondlayer. The ground layer 50 and the feed elements 51 of the patchantennas 39 are positioned at the third layer. The feed elements 51 ofthe third layer and the conductor patterns 38 of the uppermost layer areelectromagnetically coupled to each other via the openings 41 (FIG. 2B)formed in the ground layer 40 of the second layer. The conductorpatterns 38 function as passive elements. Note that power may bedirectly supplied to the conductor patterns 38.

The high-frequency device 13 and the high-frequency circuit components18 are mounted in or on the second surface 19B of the dielectricsubstrate 19. Power is supplied from the high-frequency device 13 to thefeed elements 51 via the feeders 14. The feeders 14 include interlayerconnection conductors 56, which are disposed in the dielectric substrate19, and wiring patterns 57, which are formed in or on the second surface19B.

The ground conductor columns 16 project from the second surface 19B ofthe dielectric substrate 19. The high-frequency device 13, thehigh-frequency circuit components 18, and the ground conductor columns16 are embedded in the sealing-resin layer 25. The ground layer 40 andthe ground layer 50 are connected to each other by the interlayerconnection conductors 45. The ground layer 50 and the ground conductorcolumns 16 are connected to each other by the interlayer connectionconductors 55.

A function of the wireless communication module 10 according to thesecond embodiment will now be described. The plurality of dipoleantennas 30 (FIG. 2A) function as end-fire antennas that effectivelyradiate radio waves in a direction parallel to a substrate surface ofthe dielectric substrate 19 (lateral direction). The patch antennas 39(FIG. 5B) effectively radiate radio waves in a direction normal to thesubstrate surface of the dielectric substrate 19 (boresight direction).

By adjusting the phases of signals that are supplied to the plurality ofdipole antennas 30 and the plurality of patch antennas 39, thedirectivity can be arbitrarily changed in a hemispherical plane abovethe dielectric substrate 19.

FIG. 6 is a cross-sectional view illustrating a state where the wirelesscommunication module 10 according to the second embodiment is mounted inor on the mounting substrate 20. The plurality of patch antennas 39 andthe plurality of dipole antennas 30 are disposed in or on the dielectricsubstrate 19. The high-frequency device 13 is mounted in or on thesecond surface 19B of the dielectric substrate 19.

An end of each of the signal conductor columns 15 and an end of each ofthe ground conductor columns 16 are connected to the terminals 21 of themounting substrate 20 by solder balls 27. A CPU 60 and a basebandintegrated circuit element (baseband IC) 61 are mounted in or on themounting substrate 20. The signal conductor columns 15 are connected tothe baseband integrated circuit element 61 by wiring patterns 28, whichare formed in or on the mounting substrate 20. The ground layer 22 isdisposed within the mounting substrate 20. The ground conductor columns16 are connected to the ground layer 22 by interlayer connectionconductors 23.

A transmission operation performed by the wireless communication module10 will now be described. An intermediate-frequency signal (IF signal)and a control signal are transmitted from the baseband integratedcircuit element 61 to the high-frequency device 13. The control signalincludes phase shift information of signals that are supplied to theplurality of dipole antennas 30 and the plurality of patch antennas 39and a transmission mode command. The high-frequency device 13up-converts an IF signal received thereby into a high-frequency signal(RF signal) in a millimeter-wave band. In addition, the RF signal issupplied to the plurality of dipole antennas 30 and the plurality ofpatch antennas 39 by adjusting the phase of the RF signal on the basisof the control signal. As a result, radio waves can be radiated from thedipole antennas 30 and the patch antennas 39, and the radiationintensity in a target direction can be increased.

A receiving operation performed by the wireless communication module 10will now be described. A signal that includes phase shift information ofsignals received by the plurality of dipole antennas 30 and theplurality of patch antennas 39 and a reception mode command istransmitted from the baseband integrated circuit element 61 to thehigh-frequency device 13. The high-frequency device 13 adjusts thephases of RF signals received by the plurality of dipole antennas 30 andthe plurality of patch antennas 39 and down-converts the RF signals intoIF signals. The down-converted IF signals are transmitted from thehigh-frequency device 13 to the baseband integrated circuit element 61.As a result, reception sensitivity in a target direction can beincreased.

Advantageous effects obtained by employing the configuration of thewireless communication module 10 according to the second embodiment willbe described below.

Similar to the first embodiment, in the wireless communication module 10according to the second embodiment, not only the ground layer 40 (FIG.2B) and the ground layer 50 (FIG. 3A) of the wireless communicationmodule 10 but also the ground layer 22 (FIG. 6) of the mountingsubstrate 20 operate as ground planes that are paired with the dipoleantennas 30 and the patch antennas 39 (FIG. 6). Thus, a ground planelarger than the plane dimension of the wireless communication module 10can be ensured. As a result of the ground plane becoming large, theoperations of the antennas are stabilized.

The ground layer 40 (FIG. 2B) of the wireless communication module 10,the ground conductor columns 16 (FIG. 3B), and the ground layer 22 (FIG.6) of the mounting substrate 20 serve as shield layers that shield thehigh-frequency device 13 (FIG. 6). Thus, unnecessary radiation from thehigh-frequency device 13 can be effectively blocked. In order to obtaina sufficient shielding effect, it is preferable that thecenter-to-center distance between the plurality of ground conductorcolumns 16 be one-quarter or less of the effective wavelength ofspurious radiation from the high-frequency device 13. In order tosuppress an increase in the center-to-center distance between the groundconductor columns 16, it is preferable that not more than one of thesignal conductor columns 15 be disposed between the adjacent groundconductor columns 16. In order to effectively block radiation of thesecond harmonic wave and the third harmonic wave of the spuriousradiation, it is further preferable that the center-to-center distancebetween the ground conductor columns 16 be one-twelfth or less of theeffective wavelength of the spurious radiation.

According to evaluation experiments conducted by the inventors of thepresent application, it has been found that, when the operatingfrequency of the dipole antennas 30 and the operating frequency of thepatch antennas 39 are within a bandwidth of 60 GHz, the spuriousintensity at a frequency of 30 GHz or lower is relatively high. In aregion in which the ground conductor columns 16 are disposed, theeffective wavelength of radio waves at a frequency of 30 GHz is about5.2 mm. One-quarter of the effective wavelength is about 1.3 mm, andone-twelfth of the effective wavelength is about 0.43 mm.

By injecting an underfill material between the wireless communicationmodule 10 and the mounting substrate 20 (FIG. 6), heat generated by thehigh-frequency device 13 can be effectively transferred to the mountingsubstrate 20. In addition, since the second surface 19B of thedielectric substrate 19 is coated with the sealing-resin layer 25 (FIG.4A), the coplanarity between the wireless communication module 10 andthe mounting substrate 20 can be improved.

In the second embodiment, as illustrated in FIG. 5A, the interlayerconnection conductors 35, the ground layer 40, the interlayer connectionconductors 45, the ground layer 50, the interlayer connection conductors55, and the ground conductor columns 16 are disposed below the reflectorpattern 33. These grounded conductor portions serve as reflectors forthe dipole antennas 30 (FIG. 2A). Since not only the reflector pattern33 of the uppermost layer, in or on which the dipole antennas 30 aredisposed, but also the conductor portions of the lower layers serve asreflectors, radiation efficiency (antenna gain) of the dipole antennas30 can be improved.

In order to cause the conductor portions of the lower layers to operateas reflectors, it is preferable that the reflector pattern 33, theinterlayer connection conductors 35, the ground layer 40, the interlayerconnection conductors 45, the ground layer 50, the interlayer connectionconductors 55, and the ground conductor columns 16 be arranged on avirtual plane that is parallel to the longitudinal direction of thedipole antennas 30 and perpendicular to the substrate surface of thedielectric substrate 19. It is preferable that the distance between thevirtual plane and each of the dipole antennas 30 be one-quarter or lessof the effective wavelength at the operating frequency of the dipoleantennas 30.

In the second embodiment, as illustrated in FIG. 2A, the dipole antennas30 are arranged along substantially the entire outer periphery of thedielectric substrate 19. As another configuration, the dipole antennas30 may be arranged along a portion of the outer periphery of thedielectric substrate 19. For example, a configuration may be employed inwhich the dipole antennas 30 are arranged along two adjacent sides ofthe dielectric substrate 19 and are not arranged along the other twosides.

Third Embodiment

FIG. 7A and FIG. 7B are respectively a bottom view and a cross-sectionalview of the wireless communication module 10 according to a thirdembodiment. The difference between the third embodiment and the secondembodiment, which is illustrated in FIG. 2A to FIG. 6, will be describedbelow, and the description of the configuration common to the thirdembodiment and the second embodiment will be omitted.

In the third embodiment, the frame-shaped substrate 26 is employedinstead of the sealing-resin layer 25 (FIG. 3A to FIG. 4B) according tothe second embodiment. The signal conductor columns 15 and the groundconductor columns 16 are accommodated in through holes formed in theframe-shaped substrate 26. The dielectric substrate 19 is exposed withinthe frame-shaped substrate 26. The high-frequency device 13 and thehigh-frequency circuit components 18 are disposed in a region surroundedby the frame-shaped substrate 26.

In the third embodiment, the frame-shaped substrate 26 is joined to thedielectric substrate 19 after the signal conductor columns 15 and theground conductor columns 16 have been incorporated in the frame-shapedsubstrate 26. By providing the frame-shaped substrate 26, thecoplanarity between the wireless communication module 10 and themounting substrate 20 can be improved.

Although the present disclosure has been described above on the basis ofembodiments thereof, the present disclosure is not limited to theembodiments. For example, each of the embodiments is an example, and itis obvious that the configurations according to the differentembodiments may be partially replaced with one another or may becombined with each other. In addition, it is obvious to those skilled inthe art that various changes and improvements may be made to the presentdisclosure.

-   -   10 wireless communication module    -   11 ground layer    -   12 antenna pattern    -   13 high-frequency device    -   14 feeder    -   15 signal conductor column    -   16 ground conductor column    -   17 wiring pattern    -   18 high-frequency circuit component    -   19 dielectric substrate    -   19A first surface    -   19B second surface    -   20 mounting substrate    -   21 terminal    -   22 ground layer    -   23 interlayer connection conductor    -   25 sealing-resin layer    -   26 frame-shaped substrate    -   27 solder ball    -   28 wiring pattern    -   29 conductor column    -   30 dipole antenna    -   31 feeder    -   32 balun    -   33 reflector pattern    -   34 connection point    -   35 interlayer connection conductor    -   36 connection point    -   37 conductor pattern of patch antenna (passive element)    -   38 patch antenna    -   39 ground layer    -   41, 41 opening    -   43 interlayer connection conductor    -   45 interlayer connection conductor    -   50 ground layer    -   51 feed element of patch antenna    -   52 transmission line    -   53 interlayer connection conductor    -   55, 56 interlayer connection conductor    -   57 wiring pattern    -   60 CPU    -   61 baseband integrated circuit element

1. A wireless communication module comprising: a dielectric substrate; aground layer disposed within the dielectric substrate; an antennapattern disposed so as to be closer to a first surface of the dielectricsubstrate than the ground layer is and operating as an antenna; ahigh-frequency device mounted in or on a second surface of thedielectric substrate opposite to the first surface, and supplying ahigh-frequency signal to the antenna pattern; and a plurality of signalconductor columns and a plurality of ground conductor columns projectingfrom the second surface and comprising a conductive material, whereineach of the signal conductor columns is connected to the high-frequencydevice by a wiring pattern provided in or on the dielectric substrate,wherein each of the ground conductor columns is connected to the groundlayer, and wherein an end of each of the plurality of signal conductorcolumns and an end of each of the plurality of ground conductor columnsare electrically connected to terminals of a mounting substrate, whereinthe end of at least one of the plurality of signal conductor columns isconnected to the mounting substrate by a solder bump, and wherein theend of at least one of the plurality of ground conductor columns isconnected to the mounting substrate by a solder bump.
 2. The wirelesscommunication module according to claim 1, wherein the antenna patternincludes a plurality of dipole antennas arranged along at least aportion of an outer periphery of the dielectric substrate, wherein thewireless communication module further comprises a reflector patternpositioned further inside than the dipole antennas when viewed in a planview and serving as a reflector of the dipole antennas and an interlayerconnection conductor connecting the reflector pattern to the pluralityof ground conductor columns, and wherein the ground conductor columnsserve as reflectors of the dipole antennas together with the reflectorpattern.
 3. The wireless communication module according to claim 1,wherein the antenna pattern further includes conductor patterns for aplurality of patch antennas, the conductor patterns being positionedfurther inside than the dipole antennas.
 4. The wireless communicationmodule according to claim 1, wherein the antenna pattern is configuredto operate in a bandwidth of 60 GHz, wherein the plurality of groundconductor columns are arranged so as to surround the high-frequencydevice when viewed in a plan view, and wherein a center-to-centerdistance between adjacent ones of the ground conductor columns is notmore than one-quarter of an effective wavelength of radio waves at afrequency of 30 GHz.
 5. The wireless communication module according toclaim 4, wherein the center-to-center distance between adjacent ones ofthe ground conductor columns is not more than one-twelfth of theeffective wavelength of radio waves at a frequency of 30 GHz.
 6. Thewireless communication module according to claim 1, further comprising:a sealing-resin layer disposed on the second surface of the dielectricsubstrate, wherein the high-frequency device, the signal conductorcolumns, and the ground conductor columns are embedded in thesealing-resin layer.
 7. The wireless communication module according toclaim 1, further comprising: a frame-shaped substrate joined to thesecond surface of the dielectric substrate and surrounding thehigh-frequency device when viewed in a plan view, wherein the signalconductor columns and the ground conductor columns are accommodated inthrough holes formed in the frame-shaped substrate.